Systems and methods for collision detection and avoidance

ABSTRACT

In examples, a robotic medical system comprises a link of a robotic arm and a processor configured to control movement of the link based on a received input; determine a distance between the link and another object during the movement; and, responsive to the distance being within a threshold, adjust the movement of the link to avoid a collision between the link and the another object.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.17/162,498, filed Jan. 29, 2021, which is a continuation of U.S.application Ser. No. 17/025,718, filed Sep. 18, 2020, which claims thebenefit of U.S. Provisional Application No. 62/906,612, filed Sep. 26,2019, each of which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

The systems and methods disclosed herein are directed to surgicalrobotics, and more particularly to avoiding robotic arm collisions.

BACKGROUND

Medical procedures, such as laparoscopy, may involve accessing andvisualizing an internal region of a patient. In a laparoscopicprocedure, a medical tool can be inserted into the internal regionthrough a laparoscopic cannula.

In certain procedures, a robotically-enabled medical system may be usedto control the insertion and/or manipulation of one or more medicaltool(s). The robotically-enabled medical system may have a plurality ofrobotic arms which control the medical tool(s). In positioning themedical tool(s), portion(s) of a given one of the robotic arms may movetowards another robotic arm or other object in the environment, whichcan lead to collisions.

SUMMARY

The systems, methods and devices of this disclosure each have severalinnovative aspects, no single one of which is solely responsible for thedesirable attributes disclosed herein.

In one aspect, there is provided a robotic medical system, comprising: afirst set of links; a second set of links; a console configured toreceive input commanding motion of the first set of links and the secondset of links; a processor; and at least one computer-readable memory incommunication with the processor and having stored thereon a model ofthe first set of links and the second set of links andcomputer-executable instructions to cause the processor to: access themodel of the first set of links and the second set of links, controlmovement of the first set of links and the second set of links based onthe input received by the console, determine a distance between thefirst set of links and the second set of links based on the model, andprevent a collision between the first set of links and the second set oflinks based on the determined distance.

In another aspect, there is provided a robotic medical system,comprising: a first set of links; a second set of links; a consoleconfigured to receive input commanding motion of the first set of linksand the second set of links; a processor; and at least onecomputer-readable memory in communication with the processor and havingstored thereon a model of the first set of links and the second set oflinks and computer-executable instructions to cause the processor to:control movement of the first set of links and the second set of linksbased on the input received by the console, determine a distance betweenthe first set of links and the second set of links based on the model,determine that the distance between the first set of links and thesecond set of links is less than a cutoff distance, and prevent acollision in response to determining that the distance between the firstset of links and the second set of links is less than the cutoffdistance.

In yet another aspect, there is provided a method, comprising: accessinga model of a first set of links and a second set of links of a roboticmedical system; controlling movement of the first set of links and thesecond set of links based on the input received by a console of therobotic medical system; determining a distance between the first set oflinks and the second set of links based on the model; and detecting andavoiding a collision between the first set of links and the second setof links based on the determined distance.

In still yet another aspect, there is provided a method, comprising:accessing a model of a first set of links and a second set of links of arobotic medical system; controlling movement of the first set of linksand the second set of links based on an input received by a console ofthe robotic medical system; determining a distance between the first setof links and the second set of links based on the model; determiningthat the distance between the first set of links and the second set oflinks is less than a cutoff distance; and performing an action toprevent a collision in response to determining that the distance betweenthe first set of links and the second set of links is less than thecutoff distance.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosed aspects will hereinafter be described in conjunction withthe appended drawings, provided to illustrate and not to limit thedisclosed aspects, wherein like designations denote like elements.

FIG. 1 illustrates an embodiment of a cart-based robotic system arrangedfor diagnostic and/or therapeutic bronchoscopy.

FIG. 2 depicts further aspects of the robotic system of FIG. 1 .

FIG. 3 illustrates an embodiment of the robotic system of FIG. 1arranged for ureteroscopy.

FIG. 4 illustrates an embodiment of the robotic system of FIG. 1arranged for a vascular procedure.

FIG. 5 illustrates an embodiment of a table-based robotic systemarranged for a bronchoscopic procedure.

FIG. 6 provides an alternative view of the robotic system of FIG. 5 .

FIG. 7 illustrates an example system configured to stow robotic arm(s).

FIG. 8 illustrates an embodiment of a table-based robotic systemconfigured for a ureteroscopic procedure.

FIG. 9 illustrates an embodiment of a table-based robotic systemconfigured for a laparoscopic procedure.

FIG. 10 illustrates an embodiment of the table-based robotic system ofFIGS. 5-9 with pitch or tilt adjustment.

FIG. 11 provides a detailed illustration of the interface between thetable and the column of the table-based robotic system of FIGS. 5-10 .

FIG. 12 illustrates an alternative embodiment of a table-based roboticsystem.

FIG. 13 illustrates an end view of the table-based robotic system ofFIG. 12 .

FIG. 14 illustrates an end view of a table-based robotic system withrobotic arms attached thereto.

FIG. 15 illustrates an exemplary instrument driver.

FIG. 16 illustrates an exemplary medical instrument with a pairedinstrument driver.

FIG. 17 illustrates an alternative design for an instrument driver andinstrument where the axes of the drive units are parallel to the axis ofthe elongated shaft of the instrument.

FIG. 18 illustrates an instrument having an instrument-based insertionarchitecture.

FIG. 19 illustrates an exemplary controller.

FIG. 20 depicts a block diagram illustrating a localization system thatestimates a location of one or more elements of the robotic systems ofFIGS. 1-10 , such as the location of the instrument of FIGS. 16-18 , inaccordance to an example embodiment.

FIG. 21 illustrates an example view of a model of a robotic system inaccordance with aspects of this disclosure.

FIG. 22 illustrates a model of a robotic system approximated using ageometric form in accordance with aspects of this disclosure.

FIG. 23 illustrates an example of an unavoidable collision which can bedetected using a model of a robotic system in accordance with aspects ofthis disclosure.

FIG. 24 illustrates an example of an avoidable collision which can bedetected using a model of a robotic system in accordance with aspects ofthis disclosure.

FIG. 25 is a flowchart illustrating an example method operable by arobotic system, or component(s) thereof, for detecting and avoidingcollisions in accordance with aspects of this disclosure.

FIGS. 26A and 26B illustrate an example sequence of actions when atrigger distance is reached in accordance with aspects of thisdisclosure.

FIG. 27 illustrates the cutoff and trigger distances for a modeled linkin accordance with aspects of this disclosure.

FIG. 28 is a flowchart illustrating an example method operable by arobotic system, or component(s) thereof, for detecting and avoidingcollisions using a cutoff distance in accordance with aspects of thisdisclosure.

DETAILED DESCRIPTION 1. Overview

Aspects of the present disclosure may be integrated into arobotically-enabled medical system capable of performing a variety ofmedical procedures, including both minimally invasive, such aslaparoscopy, and non-invasive, such as endoscopy, procedures. Amongendoscopic procedures, the system may be capable of performingbronchoscopy, ureteroscopy, gastroscopy, etc.

In addition to performing the breadth of procedures, the system mayprovide additional benefits, such as enhanced imaging and guidance toassist the physician. Additionally, the system may provide the physicianwith the ability to perform the procedure from an ergonomic positionwithout the need for awkward arm motions and positions. Still further,the system may provide the physician with the ability to perform theprocedure with improved ease of use such that one or more of theinstruments of the system can be controlled by a single user.

Various embodiments will be described below in conjunction with thedrawings for purposes of illustration. It should be appreciated thatmany other implementations of the disclosed concepts are possible, andvarious advantages can be achieved with the disclosed implementations.Headings are included herein for reference and to aid in locatingvarious sections. These headings are not intended to limit the scope ofthe concepts described with respect thereto. Such concepts may haveapplicability throughout the entire specification.

A. Robotic System—Cart.

The robotically-enabled medical system may be configured in a variety ofways depending on the particular procedure. FIG. 1 illustrates anembodiment of a cart-based robotically-enabled system 10 arranged for adiagnostic and/or therapeutic bronchoscopy. During a bronchoscopy, thesystem 10 may comprise a cart 11 having one or more robotic arms 12 todeliver a medical instrument, such as a steerable endoscope 13, whichmay be a procedure-specific bronchoscope for bronchoscopy, to a naturalorifice access point (i.e., the mouth of the patient positioned on atable in the present example) to deliver diagnostic and/or therapeutictools. As shown, the cart 11 may be positioned proximate to thepatient's upper torso in order to provide access to the access point.Similarly, the robotic arms 12 may be actuated to position thebronchoscope relative to the access point. The arrangement in FIG. 1 mayalso be utilized when performing a gastro-intestinal (GI) procedure witha gastroscope, a specialized endoscope for GI procedures. FIG. 2 depictsan example embodiment of the cart in greater detail.

With continued reference to FIG. 1 , once the cart 11 is properlypositioned, the robotic arms 12 may insert the steerable endoscope 13into the patient robotically, manually, or a combination thereof. Asshown, the steerable endoscope 13 may comprise at least two telescopingparts, such as an inner leader portion and an outer sheath portion, eachportion coupled to a separate instrument driver from the set ofinstrument drivers 28, each instrument driver coupled to the distal endof an individual robotic arm. This linear arrangement of the instrumentdrivers 28, which facilitates coaxially aligning the leader portion withthe sheath portion, creates a “virtual rail” 29 that may be repositionedin space by manipulating the one or more robotic arms 12 into differentangles and/or positions. The virtual rails described herein are depictedin the Figures using dashed lines, and accordingly the dashed lines donot depict any physical structure of the system. Translation of theinstrument drivers 28 along the virtual rail 29 telescopes the innerleader portion relative to the outer sheath portion or advances orretracts the endoscope 13 from the patient. The angle of the virtualrail 29 may be adjusted, translated, and pivoted based on clinicalapplication or physician preference. For example, in bronchoscopy, theangle and position of the virtual rail 29 as shown represents acompromise between providing physician access to the endoscope 13 whileminimizing friction that results from bending the endoscope 13 into thepatient's mouth.

The endoscope 13 may be directed down the patient's trachea and lungsafter insertion using precise commands from the robotic system untilreaching the target destination or operative site. In order to enhancenavigation through the patient's lung network and/or reach the desiredtarget, the endoscope 13 may be manipulated to telescopically extend theinner leader portion from the outer sheath portion to obtain enhancedarticulation and greater bend radius. The use of separate instrumentdrivers 28 also allows the leader portion and sheath portion to bedriven independently of each other.

For example, the endoscope 13 may be directed to deliver a biopsy needleto a target, such as, for example, a lesion or nodule within the lungsof a patient. The needle may be deployed down a working channel thatruns the length of the endoscope to obtain a tissue sample to beanalyzed by a pathologist. Depending on the pathology results,additional tools may be deployed down the working channel of theendoscope for additional biopsies. After identifying a nodule to bemalignant, the endoscope 13 may endoscopically deliver tools to resectthe potentially cancerous tissue. In some instances, diagnostic andtherapeutic treatments can be delivered in separate procedures. In thosecircumstances, the endoscope 13 may also be used to deliver a fiducialto “mark” the location of the target nodule as well. In other instances,diagnostic and therapeutic treatments may be delivered during the sameprocedure.

The system 10 may also include a movable tower 30, which may beconnected via support cables to the cart 11 to provide support forcontrols, electronics, fluidics, optics, sensors, and/or power to thecart 11. Placing such functionality in the tower 30 allows for a smallerform factor cart 11 that may be more easily adjusted and/orre-positioned by an operating physician and his/her staff. Additionally,the division of functionality between the cart I table and the supporttower 30 reduces operating room clutter and facilitates improvingclinical workflow. While the cart 11 may be positioned close to thepatient, the tower 30 may be stowed in a remote location to stay out ofthe way during a procedure.

In support of the robotic systems described above, the tower 30 mayinclude component(s) of a computer-based control system that storescomputer program instructions, for example, within a non-transitorycomputer-readable storage medium such as a persistent magnetic storagedrive, solid state drive, etc. The execution of those instructions,whether the execution occurs in the tower 30 or the cart 11, may controlthe entire system or sub-system(s) thereof. For example, when executedby a processor of the computer system, the instructions may cause thecomponents of the robotics system to actuate the relevant carriages andarm mounts, actuate the robotics arms, and control the medicalinstruments. For example, in response to receiving the control signal,the motors in the joints of the robotics arms may position the arms intoa certain posture.

The tower 30 may also include a pump, flow meter, valve control, and/orfluid access in order to provide controlled irrigation and aspirationcapabilities to the system that may be deployed through the endoscope13. These components may also be controlled using the computer system ofthe tower 30. In some embodiments, irrigation and aspirationcapabilities may be delivered directly to the endoscope 13 throughseparate cable(s).

The tower 30 may include a voltage and surge protector designed toprovide filtered and protected electrical power to the cart 11, therebyavoiding placement of a power transformer and other auxiliary powercomponents in the cart 11, resulting in a smaller, more moveable cart11.

The tower 30 may also include support equipment for the sensors deployedthroughout the robotic system 10. For example, the tower 30 may includeoptoelectronics equipment for detecting, receiving, and processing datareceived from the optical sensors or cameras throughout the roboticsystem 10. In combination with the control system, such optoelectronicsequipment may be used to generate real-time images for display in anynumber of consoles deployed throughout the system, including in thetower 30. Similarly, the tower 30 may also include an electronicsubsystem for receiving and processing signals received from deployedelectromagnetic (EM) sensors. The tower 30 may also be used to house andposition an EM field generator for detection by EM sensors in or on themedical instrument.

The tower 30 may also include a console 31 in addition to other consolesavailable in the rest of the system, e.g., console mounted on top of thecart. The console 31 may include a user interface and a display screen,such as a touchscreen, for the physician operator. Consoles in thesystem 10 are generally designed to provide both robotic controls aswell as preoperative and real-time information of the procedure, such asnavigational and localization information of the endoscope 13. When theconsole 31 is not the only console available to the physician, it may beused by a second operator, such as a nurse, to monitor the health orvitals of the patient and the operation of the system 10, as well as toprovide procedure-specific data, such as navigational and localizationinformation. In other embodiments, the console 30 is housed in a bodythat is separate from the tower 30.

The tower 30 may be coupled to the cart 11 and endoscope 13 through oneor more cables or connections (not shown). In some embodiments, thesupport functionality from the tower 30 may be provided through a singlecable to the cart 11, simplifying and de-cluttering the operating room.In other embodiments, specific functionality may be coupled in separatecabling and connections. For example, while power may be providedthrough a single power cable to the cart 11, the support for controls,optics, fluidics, and/or navigation may be provided through a separatecable.

FIG. 2 provides a detailed illustration of an embodiment of the cart 11from the cart-based robotically-enabled system shown in FIG. 1 . Thecart 11 generally includes an elongated support structure 14 (oftenreferred to as a “column”), a cart base 15, and a console 16 at the topof the column 14. The column 14 may include one or more carriages, suchas a carriage 17 (alternatively “arm support”) for supporting thedeployment of one or more robotic arms 12 (three shown in FIG. 2 ). Thecarriage 17 may include individually configurable arm mounts that rotatealong a perpendicular axis to adjust the base of the robotic arms 12 forbetter positioning relative to the patient. The carriage 17 alsoincludes a carriage interface 19 that allows the carriage 17 tovertically translate along the column 14.

The carriage interface 19 is connected to the column 14 through slots,such as slot 20, that are positioned on opposite sides of the column 14to guide the vertical translation of the carriage 17. The slot 20contains a vertical translation interface to position and hold thecarriage 17 at various vertical heights relative to the cart base 15.Vertical translation of the carriage 17 allows the cart 11 to adjust thereach of the robotic arms 12 to meet a variety of table heights, patientsizes, and physician preferences. Similarly, the individuallyconfigurable arm mounts on the carriage 17 allow the robotic arm base 21of the robotic arms 12 to be angled in a variety of configurations.

In some embodiments, the slot 20 may be supplemented with slot coversthat are flush and parallel to the slot surface to prevent dirt andfluid ingress into the internal chambers of the column 14 and thevertical translation interface as the carriage 17 vertically translates.The slot covers may be deployed through pairs of spring spoolspositioned near the vertical top and bottom of the slot 20. The coversare coiled within the spools until deployed to extend and retract fromtheir coiled state as the carriage 17 vertically translates up and down.The spring-loading of the spools provides force to retract the coverinto a spool when the carriage 17 translates towards the spool, whilealso maintaining a tight seal when the carriage 17 translates away fromthe spool. The covers may be connected to the carriage 17 using, forexample, brackets in the carriage interface 19 to ensure properextension and retraction of the cover as the carriage 17 translates.

The column 14 may internally comprise mechanisms, such as gears andmotors, that are designed to use a vertically aligned lead screw totranslate the carriage 17 in a mechanized fashion in response to controlsignals generated in response to user inputs, e.g., inputs from theconsole 16.

The robotic arms 12 may generally comprise robotic arm bases 21 and endeffectors 22, separated by a series of linkages 23 that are connected bya series of joints 24, each joint comprising an independent actuator,each actuator comprising an independently controllable motor. Eachindependently controllable joint represents an independentdegree-of-freedom (DoF) available to the robotic arm 12. Each of therobotic arms 12 may have seven joints, and thus provide seven degrees offreedom. A multitude of joints result in a multitude of degrees offreedom, allowing for “redundant” degrees of freedom. Having redundantdegrees of freedom allows the robotic arms 12 to position theirrespective end effectors 22 at a specific position, orientation, andtrajectory in space using different linkage positions and joint angles.This allows for the system to position and direct a medical instrumentfrom a desired point in space while allowing the physician to move thearm joints into a clinically advantageous position away from the patientto create greater access, while avoiding arm collisions.

The cart base 15 balances the weight of the column 14, carriage 17, androbotic arms 12 over the floor. Accordingly, the cart base 15 housesheavier components, such as electronics, motors, power supply, as wellas components that either enable movement and/or immobilize the cart I1.For example, the cart base 15 includes rollable wheel-shaped casters 25that allow for the cart 11 to easily move around the room prior to aprocedure. After reaching the appropriate position, the casters 25 maybe immobilized using wheel locks to hold the cart 11 in place during theprocedure.

Positioned at the vertical end of the column 14, the console 16 allowsfor both a user interface for receiving user input and a display screen(or a dual-purpose device such as, for example, a touchscreen 26) toprovide the physician user with both preoperative and intraoperativedata. Potential preoperative data on the touchscreen 26 may includepreoperative plans, navigation and mapping data derived frompreoperative computerized tomography (CT) scans, and/or notes frompreoperative patient interviews. Intraoperative data on display mayinclude optical information provided from the tool, sensor andcoordinate information from sensors, as well as vital patientstatistics, such as respiration, heart rate, and/or pulse. The console16 may be positioned and tilted to allow a physician to access theconsole 16 from the side of the column 14 opposite the carriage 17. Fromthis position, the physician may view the console 16, robotic arms 12,and patient while operating the console 16 from behind the cart 11. Asshown, the console 16 also includes a handle 27 to assist withmaneuvering and stabilizing the cart 11.

FIG. 3 illustrates an embodiment of a robotically-enabled system 10arranged for ureteroscopy. In a ureteroscopic procedure, the cart 11 maybe positioned to deliver a ureteroscope 32, a procedure-specificendoscope designed to traverse a patient's urethra and ureter, to thelower abdominal area of the patient. In a ureteroscopy, it may bedesirable for the ureteroscope 32 to be directly aligned with thepatient's urethra to reduce friction and forces on the sensitive anatomyin the area. As shown, the cart 11 may be aligned at the foot of thetable to allow the robotic arms 12 to position the ureteroscope 32 fordirect linear access to the patient's urethra. From the foot of thetable, the robotic arms 12 may insert the ureteroscope 32 along thevirtual rail 33 directly into the patient's lower abdomen through theurethra.

After insertion into the urethra, using similar control techniques as inbronchoscopy, the ureteroscope 32 may be navigated into the bladder,ureters, and/or kidneys for diagnostic and/or therapeutic applications.For example, the ureteroscope 32 may be directed into the ureter andkidneys to break up kidney stone build up using a laser or ultrasoniclithotripsy device deployed down the working channel of the ureteroscope32. After lithotripsy is complete, the resulting stone fragments may beremoved using baskets deployed down the ureteroscope 32.

FIG. 4 illustrates an embodiment of a robotically-enabled system 10similarly arranged for a vascular procedure. In a vascular procedure,the system 10 may be configured such that the cart 11 may deliver amedical instrument 34, such as a steerable catheter, to an access pointin the femoral artery in the patient's leg. The femoral artery presentsboth a larger diameter for navigation as well as a relatively lesscircuitous and tortuous path to the patient's heart, which simplifiesnavigation. As in a ureteroscopic procedure, the cart 11 may bepositioned towards the patient's legs and lower abdomen to allow therobotic arms 12 to provide a virtual rail 35 with direct linear accessto the femoral artery access point in the patient's thigh/hip region.After insertion into the artery, the medical instrument 34 may bedirected and inserted by translating the instrument drivers 28.Alternatively, the cart may be positioned around the patient's upperabdomen in order to reach alternative vascular access points, such as,for example, the carotid and brachia! arteries near the shoulder andwrist.

B. Robotic System—Table.

Embodiments of the robotically-enabled medical system may alsoincorporate the patient's table. Incorporation of the table reduces theamount of capital equipment within the operating room by removing thecart, which allows greater access to the patient. FIG. 5 illustrates anembodiment of such a robotically-enabled system arranged for abronchoscopic procedure. System 36 includes a support structure orcolumn 37 for supporting platform 38 (shown as a “table” or “bed”) overthe floor. Much like in the cart-based systems, the end effectors of therobotic arms 39 of the system 36 comprise instrument drivers 42 that aredesigned to manipulate an elongated medical instrument, such as abronchoscope 40 in FIG. 5 , through or along a virtual rail 41 formedfrom the linear alignment of the instrument drivers 42. In practice, aC-arm for providing fluoroscopic imaging may be positioned over thepatient's upper abdominal area by placing the emitter and detectoraround the table 38.

FIG. 6 provides an alternative view of the system 36 without the patientand medical instrument for discussion purposes. As shown, the column 37may include one or more carriages 43 shown as ring-shaped in the system36, from which the one or more robotic arms 39 may be based. Thecarriages 43 may translate along a vertical column interface 44 thatruns the length of the column 37 to provide different vantage pointsfrom which the robotic arms 39 may be positioned to reach the patient.The carriage(s) 43 may rotate around the column 37 using a mechanicalmotor positioned within the column 37 to allow the robotic arms 39 tohave access to multiples sides of the table 38, such as, for example,both sides of the patient. In embodiments with multiple carriages, thecarriages may be individually positioned on the column and may translateand/or rotate independently of the other carriages. While the carriages43 need not surround the column 37 or even be circular, the ring-shapeas shown facilitates rotation of the carriages 43 around the column 37while maintaining structural balance. Rotation and translation of thecarriages 43 allows the system 36 to align the medical instruments, suchas endoscopes and laparoscopes, into different access points on thepatient. In other embodiments (not shown), the system 36 can include apatient table or bed with adjustable arm supports in the form of bars orrails extending alongside it. One or more robotic arms 39 (e.g., via ashoulder with an elbow joint) can be attached to the adjustable armsupports, which can be vertically adjusted. By providing verticaladjustment, the robotic arms 39 are advantageously capable of beingstowed compactly beneath the patient table or bed, and subsequentlyraised during a procedure.

The robotic arms 39 may be mounted on the carriages 43 through a set ofarm mounts 45 comprising a series of joints that may individually rotateand/or telescopically extend to provide additional configurability tothe robotic arms 39. Additionally, the arm mounts 45 may be positionedon the carriages 43 such that, when the carriages 43 are appropriatelyrotated, the arm mounts 45 may be positioned on either the same side ofthe table 38 (as shown in FIG. 6 ), on opposite sides of the table 38(as shown in FIG. 9 ), or on adjacent sides of the table 38 (not shown).

The column 37 structurally provides support for the table 38, and a pathfor vertical translation of the carriages 43. Internally, the column 37may be equipped with lead screws for guiding vertical translation of thecarriages, and motors to mechanize the translation of the carriages 43based the lead screws. The column 37 may also convey power and controlsignals to the carriages 43 and the robotic arms 39 mounted thereon.

The table base 46 serves a similar function as the cart base 15 in thecart 11 shown in FIG. 2 , housing heavier components to balance thetable/bed 38, the column 37, the carriages 43, and the robotic arms 39.The table base 46 may also incorporate rigid casters to providestability during procedures. Deployed from the bottom of the table base46, the casters may extend in opposite directions on both sides of thebase 46 and retract when the system 36 needs to be moved.

With continued reference to FIG. 6 , the system 36 may also include atower (not shown) that divides the functionality of the system 36between the table and the tower to reduce the form factor and bulk ofthe table. As in earlier disclosed embodiments, the tower may provide avariety of support functionalities to the table, such as processing,computing, and control capabilities, power, fluidics, and/or optical andsensor processing. The tower may also be movable to be positioned awayfrom the patient to improve physician access and de-clutter theoperating room. Additionally, placing components in the tower allows formore storage space in the table base 46 for potential stowage of therobotic arms 39. The tower may also include a master controller orconsole that provides both a user interface for user input, such askeyboard and/or pendant, as well as a display screen (or touchscreen)for preoperative and intraoperative information, such as real-timeimaging, navigation, and tracking information. In some embodiments, thetower may also contain holders for gas tanks to be used forinsufflation.

In some embodiments, a table base may stow and store the robotic armswhen not in use. FIG. 7 illustrates a system 47 that stows robotic armsin an embodiment of the table-based system. In the system 47, carriages48 may be vertically translated into base 49 to stow robotic arms 50,arm mounts 51, and the carriages 48 within the base 49. Base covers 52may be translated and retracted open to deploy the carriages 48, armmounts 51, and robotic arms 50 around column 53, and closed to stow toprotect them when not in use. The base covers 52 may be sealed with amembrane 54 along the edges of its opening to prevent dirt and fluidingress when closed.

FIG. 8 illustrates an embodiment of a robotically-enabled table-basedsystem configured for a ureteroscopic procedure. In a ureteroscopy, thetable 38 may include a swivel portion 55 for positioning a patientoff-angle from the column 37 and table base 46. The swivel portion 55may rotate or pivot around a pivot point (e.g., located below thepatient's head) in order to position the bottom portion of the swivelportion 55 away from the column 37. For example, the pivoting of theswivel portion 55 allows a C-arm (not shown) to be positioned over thepatient's lower abdomen without competing for space with the column (notshown) below table 38. By rotating the carriage 35 (not shown) aroundthe column 37, the robotic arms 39 may directly insert a ureteroscope 56along a virtual rail 57 into the patient's groin area to reach theurethra. In a ureteroscopy, stirrups 58 may also be fixed to the swivelportion 55 of the table 38 to support the position of the patient's legsduring the procedure and allow clear access to the patient's groin area.

In a laparoscopic procedure, through small incision(s) in the patient'sabdominal wall, minimally invasive instruments may be inserted into thepatient's anatomy. In some embodiments, the minimally invasiveinstruments comprise an elongated rigid member, such as a shaft, whichis used to access anatomy within the patient. After inflation of thepatient's abdominal cavity, the instruments may be directed to performsurgical or medical tasks, such as grasping, cutting, ablating,suturing, etc. In some embodiments, the instruments can comprise ascope, such as a laparoscope. FIG. 9 illustrates an embodiment of arobotically-enabled table-based system configured for a laparoscopicprocedure. As shown in FIG. 9 , the carriages 43 of the system 36 may berotated and vertically adjusted to position pairs of the robotic arms 39on opposite sides of the table 38, such that instrument 59 may bepositioned using the arm mounts 45 to be passed through minimalincisions on both sides of the patient to reach his/her abdominalcavity.

To accommodate laparoscopic procedures, the robotically-enabled tablesystem may also tilt the platform to a desired angle. FIG. 10illustrates an embodiment of the robotically-enabled medical system withpitch or tilt adjustment. As shown in FIG. 10 , the system 36 mayaccommodate tilt of the table 38 to position one portion of the table ata greater distance from the floor than the other. Additionally, the armmounts 45 may rotate to match the tilt such that the robotic arms 39maintain the same planar relationship with the table 38. To accommodatesteeper angles, the column 37 may also include telescoping portions 60that allow vertical extension of the column 37 to keep the table 38 fromtouching the floor or colliding with the table base 46.

FIG. 11 provides a detailed illustration of the interface between thetable 38 and the column 37. Pitch rotation mechanism 61 may beconfigured to alter the pitch angle of the table 38 relative to thecolumn 37 in multiple degrees of freedom. The pitch rotation mechanism61 may be enabled by the positioning of orthogonal axes 1, 2 at thecolumn-table interface, each axis actuated by a separate motor 3, 4responsive to an electrical pitch angle command. Rotation along onescrew 5 would enable tilt adjustments in one axis 1, while rotationalong the other screw 6 would enable tilt adjustments along the otheraxis 2. In some embodiments, a ball joint can be used to alter the pitchangle of the table 38 relative to the column 37 in multiple degrees offreedom.

For example, pitch adjustments are particularly useful when trying toposition the table in a Trendelenburg position, i.e., position thepatient's lower abdomen at a higher position from the floor than thepatient's upper abdomen, for lower abdominal surgery. The Trendelenburgposition causes the patient's internal organs to slide towards his/herupper abdomen through the force of gravity, clearing out the abdominalcavity for minimally invasive tools to enter and perform lower abdominalsurgical or medical procedures, such as laparoscopic prostatectomy.

FIGS. 12 and 13 illustrate isometric and end views of an alternativeembodiment of a table-based surgical robotics system 100. The surgicalrobotics system 100 includes one or more adjustable arm supports 105that can be configured to support one or more robotic arms (see, forexample, FIG. 14 ) relative to a table 101. In the illustratedembodiment, a single adjustable arm support 105 is shown, though anadditional arm support can be provided on an opposite side of the table101. The adjustable arm support 105 can be configured so that it canmove relative to the table IOI to adjust and/or vary the position of theadjustable arm support 105 and/or any robotic arms mounted theretorelative to the table 101. For example, the adjustable arm support 105may be adjusted one or more degrees of freedom relative to the table101. The adjustable arm support 105 provides high versatility to thesystem 100, including the ability to easily stow the one or moreadjustable arm supports 105 and any robotics arms attached theretobeneath the table 101. The adjustable arm support 105 can be elevatedfrom the stowed position to a position below an upper surface of thetable IO1. In other embodiments, the adjustable arm support 105 can beelevated from the stowed position to a position above an upper surfaceof the table IO1.

The adjustable arm support 105 can provide several degrees of freedom,including lift, lateral translation, tilt, etc. In the illustratedembodiment of FIGS. 12 and 13 , the arm support 105 is configured withfour degrees of freedom, which are illustrated with arrows in FIG. 12 .A first degree of freedom allows for adjustment of the adjustable armsupport 105 in the z-direction (“Z-lift”). For example, the adjustablearm support 105 can include a carriage 109 configured to move up or downalong or relative to a column 102 supporting the table 101. A seconddegree of freedom can allow the adjustable arm support 105 to tilt. Forexample, the adjustable arm support 105 can include a rotary joint,which can allow the adjustable arm support 105 to be aligned with thebed in a Trendelenburg position. A third degree of freedom can allow theadjustable arm support 105 to “pivot up,” which can be used to adjust adistance between a side of the table 101 and the adjustable arm support105. A fourth degree of freedom can permit translation of the adjustablearm support 105 along a longitudinal length of the table.

The surgical robotics system 100 in FIGS. 12 and 13 can comprise a tablesupported by a column 102 that is mounted to a base 103. The base 103and the column 102 support the table 10 I relative to a support surface.A floor axis 131 and a support axis 133 are shown in FIG. 13 .

The adjustable arm support 105 can be mounted to the column 102. Inother embodiments, the arm support 105 can be mounted to the table 101or base 103. The adjustable arm support 105 can include a carriage 109,a bar or rail connector 111 and a bar or rail 107. In some embodiments,one or more robotic arms mounted to the rail 107 can translate and moverelative to one another.

The carriage 109 can be attached to the column 102 by a first joint 113,which allows the carriage 109 to move relative to the column 102 (e.g.,such as up and down a first or vertical axis 123). The first joint 113can provide the first degree of freedom (“Z-lift”) to the adjustable armsupport 105. The adjustable arm support 105 can include a second joint115, which provides the second degree of freedom (tilt) for theadjustable arm support 105. The adjustable arm support 105 can include athird joint 117, which can provide the third degree of freedom (“pivotup”) for the adjustable arm support 105. An additional joint 119 (shownin FIG. 13 ) can be provided that mechanically constrains the thirdjoint 117 to maintain an orientation of the rail 107 as the railconnector 111 is rotated about a third axis 127. The adjustable armsupport 105 can include a fourth joint 121, which can provide a fourthdegree of freedom (translation) for the adjustable arm support 105 alonga fourth axis 129.

FIG. 14 illustrates an end view of the surgical robotics system 140Awith two adjustable arm supports 105A, 105B mounted on opposite sides ofa table 101. A first robotic arm 142A is attached to the bar or rail107A of the first adjustable arm support 105B. The first robotic arm142A includes a base 144A attached to the rail 107A. The distal end ofthe first robotic arm 142A includes an instrument drive mechanism 146Athat can attach to one or more robotic medical instruments or tools.Similarly, the second robotic arm 142B includes a base 144B attached tothe rail 107B. The distal end of the second robotic arm 142B includes aninstrument drive mechanism 146B. The instrument drive mechanism 146B canbe configured to attach to one or more robotic medical instruments ortools.

In some embodiments, one or more of the robotic arms 142A, 142Bcomprises an arm with seven or more degrees of freedom. In someembodiments, one or more of the robotic arms 142A, 142B can includeeight degrees of freedom, including an insertion axis (1-degree offreedom including insertion), a wrist (3-degrees of freedom includingwrist pitch, yaw and roll), an elbow (1-degree of freedom includingelbow pitch), a shoulder (2-degrees of freedom including shoulder pitchand yaw), and base 144A, 144B (1-degree of freedom includingtranslation). In some embodiments, the insertion degree of freedom canbe provided by the robotic arm 142A, 142B, while in other embodiments,the instrument itself provides insertion via an instrument-basedinsertion architecture.

C. Instrument Driver & Interface.

The end effectors of the system's robotic arms may comprise (i) aninstrument driver (alternatively referred to as “instrument drivemechanism” or “instrument device manipulator”) that incorporateselectro-mechanical means for actuating the medical instrument and (ii) aremovable or detachable medical instrument, which may be devoid of anyelectro-mechanical components, such as motors. This dichotomy may bedriven by the need to sterilize medical instruments used in medicalprocedures, and the inability to adequately sterilize expensive capitalequipment due to their intricate mechanical assemblies and sensitiveelectronics. Accordingly, the medical instruments may be designed to bedetached, removed, and interchanged from the instrument driver (and thusthe system) for individual sterilization or disposal by the physician orthe physician's staff. In contrast, the instrument drivers need not bechanged or sterilized, and may be draped for protection.

FIG. 15 illustrates an example instrument driver. Positioned at thedistal end of a robotic arm, instrument driver 62 comprises one or moredrive units 63 arranged with parallel axes to provide controlled torqueto a medical instrument via drive shafts 64. Each drive unit 63comprises an individual drive shaft 64 for interacting with theinstrument, a gear head 65 for converting the motor shaft rotation to adesired torque, a motor 66 for generating the drive torque, an encoder67 to measure the speed of the motor shaft and provide feedback to thecontrol circuitry, and control circuitry 68 for receiving controlsignals and actuating the drive unit. Each drive unit 63 beingindependently controlled and motorized, the instrument driver 62 mayprovide multiple (e.g., four as shown in FIG. 15 ) independent driveoutputs to the medical instrument. In operation, the control circuitry68 would receive a control signal, transmit a motor signal to the motor66, compare the resulting motor speed as measured by the encoder 67 withthe desired speed, and modulate the motor signal to generate the desiredtorque.

For procedures that require a sterile environment, the robotic systemmay incorporate a drive interface, such as a sterile adapter connectedto a sterile drape, that sits between the instrument driver and themedical instrument. The chief purpose of the sterile adapter is totransfer angular motion from the drive shafts of the instrument driverto the drive inputs of the instrument while maintaining physicalseparation, and thus sterility, between the drive shafts and driveinputs. Accordingly, an example sterile adapter may comprise a series ofrotational inputs and outputs intended to be mated with the drive shaftsof the instrument driver and drive inputs on the instrument. Connectedto the sterile adapter, the sterile drape, comprised of a thin, flexiblematerial such as transparent or translucent plastic, is designed tocover the capital equipment, such as the instrument driver, robotic arm,and cart (in a cart-based system) or table (in a table-based system).Use of the drape would allow the capital equipment to be positionedproximate to the patient while still being located in an area notrequiring sterilization (i.e., non-sterile field). On the other side ofthe sterile drape, the medical instrument may interface with the patientin an area requiring sterilization (i.e., sterile field).

D. Medical Instrument.

FIG. 16 illustrates an example medical instrument with a pairedinstrument driver. Like other instruments designed for use with arobotic system, medical instrument 70 comprises an elongated shaft 71(or elongate body) and an instrument base 72. The instrument base 72,also referred to as an “instrument handle” due to its intended designfor manual interaction by the physician, may generally compriserotatable drive inputs 73, e.g., receptacles, pulleys or spools, thatare designed to be mated with drive outputs 74 that extend through adrive interface on instrument driver 75 at the distal end of robotic arm76. When physically connected, latched, and/or coupled, the mated driveinputs 73 of the instrument base 72 may share axes of rotation with thedrive outputs 74 in the instrument driver 75 to allow the transfer oftorque from the drive outputs 74 to the drive inputs 73. In someembodiments, the drive outputs 74 may comprise splines that are designedto mate with receptacles on the drive inputs 73.

The elongated shaft 71 is designed to be delivered through either ananatomical opening or lumen, e.g., as in endoscopy, or a minimallyinvasive incision, e.g., as in laparoscopy. The elongated shaft 71 maybe either flexible (e.g., having properties similar to an endoscope) orrigid (e.g., having properties similar to a laparoscope) or contain acustomized combination of both flexible and rigid portions. Whendesigned for laparoscopy, the distal end of a rigid elongated shaft maybe connected to an end effector extending from a jointed wrist formedfrom a clevis with at least one degree of freedom and a surgical tool ormedical instrument, such as, for example, a grasper or scissors, thatmay be actuated based on force from the tendons as the drive inputsrotate in response to torque received from the drive outputs 74 of theinstrument driver 75. When designed for endoscopy, the distal end of aflexible elongated shaft may include a steerable or controllable bendingsection that may be articulated and bent based on torque received fromthe drive outputs 74 of the instrument driver 75.

Torque from the instrument driver 75 is transmitted down the elongatedshaft 71 using tendons along the elongated shaft 71. These individualtendons, such as pull wires, may be individually anchored to individualdrive inputs 73 within the instrument handle 72. From the handle 72, thetendons are directed down one or more pull lumens along the elongatedshaft 71 and anchored at the distal portion of the elongated shaft 71,or in the wrist at the distal portion of the elongated shaft. During asurgical procedure, such as a laparoscopic, endoscopic or hybridprocedure, these tendons may be coupled to a distally mounted endeffector, such as a wrist, grasper, or scissor. Under such anarrangement, torque exerted on drive inputs 73 would transfer tension tothe tendon, thereby causing the end effector to actuate in some way. Insome embodiments, during a surgical procedure, the tendon may cause ajoint to rotate about an axis, thereby causing the end effector to movein one direction or another. Alternatively, the tendon may be connectedto one or more jaws of a grasper at the distal end of the elongatedshaft 71, where tension from the tendon causes the grasper to close.

In endoscopy, the tendons may be coupled to a bending or articulatingsection positioned along the elongated shaft 71 (e.g., at the distalend) via adhesive, control ring, or other mechanical fixation. Whenfixedly attached to the distal end of a bending section, torque exertedon the drive inputs 73 would be transmitted down the tendons, causingthe softer, bending section (sometimes referred to as the articulablesection or region) to bend or articulate. Along the non-bendingsections, it may be advantageous to spiral or helix the individual pulllumens that direct the individual tendons along (or inside) the walls ofthe endoscope shaft to balance the radial forces that result fromtension in the pull wires. The angle of the spiraling and/or spacingtherebetween may be altered or engineered for specific purposes, whereintighter spiraling exhibits lesser shaft compression under load forces,while lower amounts of spiraling results in greater shaft compressionunder load forces, but limits bending. On the other end of the spectrum,the pull lumens may be directed parallel to the longitudinal axis of theelongated shaft 71 to allow for controlled articulation in the desiredbending or articulable sections.

In endoscopy, the elongated shaft 71 houses a number of components toassist with the robotic procedure. The shaft 71 may comprise a workingchannel for deploying surgical tools (or medical instruments),irrigation, and/or aspiration to the operative region at the distal endof the shaft 71. The shaft 71 may also accommodate wires and/or opticalfibers to transfer signals to/from an optical assembly at the distaltip, which may include an optical camera. The shaft 71 may alsoaccommodate optical fibers to carry light from proximally-located lightsources, such as light emitting diodes, to the distal end of the shaft71.

At the distal end of the instrument 70, the distal tip may also comprisethe opening of a working channel for delivering tools for diagnosticand/or therapy, irrigation, and aspiration to an operative site. Thedistal tip may also include a port for a camera, such as a fiberscope ora digital camera, to capture images of an internal anatomical space.Relatedly, the distal tip may also include ports for light sources forilluminating the anatomical space when using the camera.

In the example of FIG. 16 , the drive shaft axes, and thus the driveinput axes, are orthogonal to the axis of the elongated shaft 71. Thisarrangement, however, complicates roll capabilities for the elongatedshaft 71. Rolling the elongated shaft 71 along its axis while keepingthe drive inputs 73 static results in undesirable tangling of thetendons as they extend off the drive inputs 73 and enter pull lumenswithin the elongated shaft 71. The resulting entanglement of suchtendons may disrupt any control algorithms intended to predict movementof the flexible elongated shaft 71 during an endoscopic procedure.

FIG. 17 illustrates an alternative design for an instrument driver andinstrument where the axes of the drive units are parallel to the axis ofthe elongated shaft of the instrument. As shown, a circular instrumentdriver 80 comprises four drive units with their drive outputs 81 alignedin parallel at the end of a robotic arm 82. The drive units, and theirrespective drive outputs 81, are housed in a rotational assembly 83 ofthe instrument driver 80 that is driven by one of the drive units withinthe assembly 83. In response to torque provided by the rotational driveunit, the rotational assembly 83 rotates along a circular bearing thatconnects the rotational assembly 83 to the non-rotational portion 84 ofthe instrument driver 80. Power and controls signals may be communicatedfrom the non-rotational portion 84 of the instrument driver 80 to therotational assembly 83 through electrical contacts that may bemaintained through rotation by a brushed slip ring connection (notshown). In other embodiments, the rotational assembly 83 may beresponsive to a separate drive unit that is integrated into thenon-rotatable portion 84, and thus not in parallel to the other driveunits. The rotational mechanism 83 allows the instrument driver 80 torotate the drive units, and their respective drive outputs 81, as asingle unit around an instrument driver axis 85.

Like earlier disclosed embodiments, an instrument 86 may comprise anelongated shaft portion 88 and an instrument base 87 (shown with atransparent external skin for discussion purposes) comprising aplurality of drive inputs 89 (such as receptacles, pulleys, and spools)that are configured to receive the drive outputs 81 in the instrumentdriver 80. Unlike prior disclosed embodiments, the instrument shaft 88extends from the center of the instrument base 87 with an axissubstantially parallel to the axes of the drive inputs 89, rather thanorthogonal as in the design of FIG. 16 .

When coupled to the rotational assembly 83 of the instrument driver 80,the medical instrument 86, comprising instrument base 87 and instrumentshaft 88, rotates in combination with the rotational assembly 83 aboutthe instrument driver axis 85. Since the instrument shaft 88 ispositioned at the center of instrument base 87, the instrument shaft 88is coaxial with instrument driver axis 85 when attached. Thus, rotationof the rotational assembly 83 causes the instrument shaft 88 to rotateabout its own longitudinal axis. Moreover, as the instrument base 87rotates with the instrument shaft 88, any tendons connected to the driveinputs 89 in the instrument base 87 are not tangled during rotation.Accordingly, the parallelism of the axes of the drive outputs 81, driveinputs 89, and instrument shaft 88 allows for the shaft rotation withouttangling any control tendons.

FIG. 18 illustrates an instrument having an instrument based insertionarchitecture in accordance with some embodiments. The instrument 150 canbe coupled to any of the instrument drivers discussed above. Theinstrument 150 comprises an elongated shaft 152, an end effector 162connected to the shaft 152, and a handle 170 coupled to the shaft 152.The elongated shaft 152 comprises a tubular member having a proximalportion 154 and a distal portion 156. The elongated shaft 152 comprisesone or more channels or grooves 158 along its outer surface. The grooves158 are configured to receive one or more wires or cables 180therethrough. One or more cables 180 thus run along an outer surface ofthe elongated shaft 152. In other embodiments, cables 180 can also runthrough the elongated shaft 152. Manipulation of the one or more cables180 (e.g., via an instrument driver) results in actuation of the endeffector 162.

The instrument handle 170, which may also be referred to as aninstrument base, may generally comprise an attachment interface 172having one or more mechanical inputs 174, e.g., receptacles, pulleys orspools, that are designed to be reciprocally mated with one or moretorque couplers on an attachment surface of an instrument driver.

In some embodiments, the instrument 150 comprises a series of pulleys orcables that enable the elongated shaft 152 to translate relative to thehandle 170. In other words, the instrument 150 itself comprises aninstrument-based insertion architecture that accommodates insertion ofthe instrument, thereby minimizing the reliance on a robot arm toprovide insertion of the instrument 150. In other embodiments, a roboticarm can be largely responsible for instrument insertion.

E. Controller.

Any of the robotic systems described herein can include an input deviceor controller for manipulating an instrument attached to a robotic arm.In some embodiments, the controller can be coupled (e.g.,communicatively, electronically, electrically, wirelessly and/ormechanically) with an instrument such that manipulation of thecontroller causes a corresponding manipulation of the instrument e.g.,via master slave control.

FIG. 19 is a perspective view of an embodiment of a controller 182. Inthe present embodiment, the controller 182 comprises a hybrid controllerthat can have both impedance and admittance control. In otherembodiments, the controller 182 can utilize just impedance or passivecontrol. In other embodiments, the controller 182 can utilize justadmittance control. By being a hybrid controller, the controller 182advantageously can have a lower perceived inertia while in use.

In the illustrated embodiment, the controller 182 is configured to allowmanipulation of two medical instruments, and includes two handles 184.Each of the handles 184 is connected to a gimbal 186. Each gimbal 186 isconnected to a positioning platform 188.

As shown in FIG. 19 , each positioning platform 188 includes a SCARA arm(selective compliance assembly robot arm) 198 coupled to a column 194 bya prismatic joint 196. The prismatic joints 196 are configured totranslate along the column 194 (e.g., along rails 197) to allow each ofthe handles 184 to be translated in the z-direction, providing a firstdegree of freedom. The SCARA arm 198 is configured to allow motion ofthe handle 184 in an x-y plane, providing two additional degrees offreedom.

In some embodiments, one or more load cells are positioned in thecontroller. For example, in some embodiments, a load cell (not shown) ispositioned in the body of each of the gimbals 186. By providing a loadcell, portions of the controller 182 are capable of operating underadmittance control, thereby advantageously reducing the perceivedinertia of the controller while in use. In some embodiments, thepositioning platform 188 is configured for admittance control, while thegimbal 186 is configured for impedance control. In other embodiments,the gimbal 186 is configured for admittance control, while thepositioning platform 188 is configured for impedance control.Accordingly, for some embodiments, the translational or positionaldegrees of freedom of the positioning platform 188 can rely onadmittance control, while the rotational degrees of freedom of thegimbal 186 rely on impedance control.

F. Navigation and Control.

Traditional endoscopy may involve the use of fluoroscopy (e.g., as maybe delivered through a C-arm) and other forms of radiation-based imagingmodalities to provide endoluminal guidance to an operator physician. Incontrast, the robotic systems contemplated by this disclosure canprovide for non-radiation-based navigational and localization means toreduce physician exposure to radiation and reduce the amount ofequipment within the operating room. As used herein, the term“localization” may refer to determining and/or monitoring the positionof objects in a reference coordinate system. Technologies such aspreoperative mapping, computer vision, real-time EM tracking, and robotcommand data may be used individually or in combination to achieve aradiation-free operating environment. In other cases, whereradiation-based imaging modalities are still used, the preoperativemapping, computer vision, real-time EM tracking, and robot command datamay be used individually or in combination to improve upon theinformation obtained solely through radiation-based imaging modalities.

FIG. 20 1 s a block diagram illustrating a localization system 90 thatestimates a location of one or more elements of the robotic system, suchas the location of the instrument, in accordance to an exampleembodiment. The localization system 90 may be a set of one or morecomputer devices configured to execute one or more instructions. Thecomputer devices may be embodied by a processor (or processors) andcomputer-readable memory in one or more components discussed above. Byway of example and not limitation, the computer devices may be in thetower 30 shown in FIG. 1 , the cart 11 shown in FIGS. 1-4 , the bedsshown in FIGS. 5-14 , etc.

As shown in FIG. 20 , the localization system 90 may include alocalization module 95 that processes input data 91-94 to generatelocation data 96 for the distal tip of a medical instrument. Thelocation data 96 may be data or logic that represents a location and/ororientation of the distal end of the instrument relative to a frame ofreference. The frame of reference can be a frame of reference relativeto the anatomy of the patient or to a known object, such as an EM fieldgenerator (see discussion below for the EM field generator).

The various input data 91-94 are now described in greater detail.Preoperative mapping may be accomplished through the use of thecollection of low dose CT scans. Preoperative CT scans are reconstructedinto three-dimensional images, which are visualized, e.g. as “slices” ofa cutaway view of the patient's internal anatomy. When analyzed in theaggregate, image-based models for anatomical cavities, spaces andstructures of the patient's anatomy, such as a patient lung network, maybe generated. Techniques such as center-line geometry may be determinedand approximated from the CT images to develop a three-dimensionalvolume of the patient's anatomy, referred to as model data 91 (alsoreferred to as “preoperative model data” when generated using onlypreoperative CT scans). The use of center-line geometry is discussed inU.S. patent application Ser. No. 14/523,760, the contents of which areherein incorporated in its entirety. Network topological models may alsobe derived from the CT-images, and are particularly appropriate forbronchoscopy.

In some embodiments, the instrument may be equipped with a camera toprovide vision data (or image data) 92. The localization module 95 mayprocess the vision data 92 to enable one or more vision-based (orimage-based) location tracking modules or features. For example, thepreoperative model data 91 may be used in conjunction with the visiondata 92 to enable computer vision-based tracking of the medicalinstrument (e.g., an endoscope or an instrument advance through aworking channel of the endoscope). For example, using the preoperativemodel data 91, the robotic system may generate a library of expectedendoscopic images from the model based on the expected path of travel ofthe endoscope, each image linked to a location within the model.Intraoperatively, this library may be referenced by the robotic systemin order to compare real-time images captured at the camera (e.g., acamera at a distal end of the endoscope) to those in the image libraryto assist localization.

Other computer vision-based tracking techniques use feature tracking todetermine motion of the camera, and thus the endoscope. Some features ofthe localization module 95 may identify circular geometries in thepreoperative model data 91 that correspond to anatomical lumens andtrack the change of those geometries to determine which anatomical lumenwas selected, as well as the relative rotational and/or translationalmotion of the camera. Use of a topological map may further enhancevision-based algorithms or techniques.

Optical flow, another computer vision-based technique, may analyze thedisplacement and translation of image pixels in a video sequence in thevision data 92 to infer camera movement. Examples of optical flowtechniques may include motion detection, object segmentationcalculations, luminance, motion compensated encoding, stereo disparitymeasurement, etc. Through the comparison of multiple frames overmultiple iterations, movement and location of the camera (and thus theendoscope) may be determined.

The localization module 95 may use real-time EM tracking to generate areal-time location of the endoscope in a global coordinate system thatmay be registered to the patient's anatomy, represented by thepreoperative model. In EM tracking, an EM sensor (or tracker) comprisingone or more sensor coils embedded in one or more locations andorientations in a medical instrument (e.g., an endoscopic tool) measuresthe variation in the EM field created by one or more static EM fieldgenerators positioned at a known location. The location informationdetected by the EM sensors is stored as EM data 93. The EM fieldgenerator (or transmitter), may be placed close to the patient to createa low intensity magnetic field that the embedded sensor may detect. Themagnetic field induces small currents in the sensor coils of the EMsensor, which may be analyzed to determine the distance and anglebetween the EM sensor and the EM field generator. These distances andorientations may be intraoperatively “registered” to the patient anatomy(e.g., the preoperative model) in order to determine the geometrictransformation that aligns a single location in the coordinate systemwith a position in the preoperative model of the patient's anatomy. Onceregistered, an embedded EM tracker in one or more positions of themedical instrument (e.g., the distal tip of an endoscope) may providereal-time indications of the progression of the medical instrumentthrough the patient's anatomy.

Robotic command and kinematics data 94 may also be used by thelocalization module 95 to provide localization data 96 for the roboticsystem. Device pitch and yaw resulting from articulation commands may bedetermined during preoperative calibration. Intraoperatively, thesecalibration measurements may be used in combination with known insertiondepth information to estimate the position of the instrument.Alternatively, these calculations may be analyzed in combination withEM, vision, and/or topological modeling to estimate the position of themedical instrument within the network.

As FIG. 20 shows, a number of other input data can be used by thelocalization module 95. For example, although not shown in FIG. 20 , aninstrument utilizing shape-sensing fiber can provide shape data that thelocalization module 95 can use to determine the location and shape ofthe instrument.

The localization module 95 may use the input data 91-94 incombination(s). In some cases, such a combination may use aprobabilistic approach where the localization module 95 assigns aconfidence weight to the location determined from each of the input data91-94. Thus, where the EM data may not be reliable (as may be the casewhere there is EM interference) the confidence of the locationdetermined by the EM data 93 can be decrease and the localization module95 may rely more heavily on the vision data 92 and/or the roboticcommand and kinematics data 94.

As discussed above, the robotic systems discussed herein may be designedto incorporate a combination of one or more of the technologies above.The robotic system's computer-based control system, based in the tower,bed and/or cart, may store computer program instructions, for example,within a non-transitory computer-readable storage medium such as apersistent magnetic storage drive, solid state drive, or the like, that,upon execution, cause the system to receive and analyze sensor data anduser commands, generate control signals throughout the system, anddisplay the navigational and localization data, such as the position ofthe instrument within the global coordinate system, anatomical map, etc.

2. Introduction to Systems and Methods for Collision Avoidance

The present disclosure relates to systems and techniques for collisionavoidance. Robotic arms may be used to achieve a desired pose (i.e.,position and orientation) of an end effector of a medical tool. In someimplementations, the medical tool may include a medical instrument or acamera. In manipulating a robotic arm to achieve the desired endeffector pose, there may be a risk that some portion of the robotic armis moved into a pose that would collide with another nearby object(e.g., another robotic arm, the patient, a platform supporting thepatient, medical accessories attached to the platform, etc.).

One way to avoid robotic arm collisions is to position the robotic armsand access points during a pre-procedure set up, e.g., prior toperforming a medical procedure, in such a way that the robotic arms areunlikely to be placed into a pose that would result in a collision withother object(s). However, pre-procedure placement or positioning maylimit the options for robotic arm placement and/or access pointplacement. For example, in some instances robotic arms and access pointsmay be spaced apart by minimum distances in order to reduce thelikelihood of collisions therebetween. However, such spacing of therobotic arms and/or access points may reduce the ability of the user toposition medical tool(s) in desired pose(s). For example, certainprocedures for patients of certain sizes (e.g., smaller patients) mayinvolve close spacing of ports to form access points into the patient'sanatomy. In these cases, it may not be possible to place the roboticarms and/or access points in locations that reduce the likelihood ofrobotic arm collisions.

During certain medical procedures, it can be beneficial to have multiplerobotic arms in very close proximity, for example, when access pointsare placed in close proximity. It can also be beneficial to provideclinicians with the ability to change the anatomical quadrant they areworking in while also providing as much room as possible to operate. Incontrolling the robotic arms in accordance with one or more of the aboveconstraints, collisions between the robotic arms may be more likely tooccur, which can interrupt workflow. Thus, it can be desirable tomitigate the likelihood of collisions between the robotic arms, reducingthe likelihood of workflow interruptions.

There may be challenges for clinicians to manually mitigate collisionsbetween robotic arms and/or with other objects. Clinicians may operatethe system with their head down in a viewer, which may prevent theclinician from seeing the robotic arms outside of the patient's body.Furthermore, each robotic arm may have a plurality of possible positionsthat achieve the same end effector pose due to the inclusion ofredundant DoFs in the robotic arm(s). Thus, it may not be immediatelyapparent to the clinician what robotic arm motions outside of the bodywill result from the commanded end effector motions inside of the body.The result is that robotic arms may collide with another object withoutthe clinician being able to predict the collision, and it may requiretime and mental effort for the clinician to determine possible movementsof the end effectors that will position the robotic arms back into goodworking location(s). If the clinician is unable to reposition therobotic arms back into good working location(s), the clinician may pausethe medical procedure in order to relocate the robotic arms intopositions and port placements that will not result in robotic armcollisions.

For some robotic systems that include robotic arms that are heavy andbulky, certain collisions may be allowed. However, for robotic systemsthat have robotic arms that are of a sleek and elegant design, such asthe robotic arms 142A, 142B of FIG. 14 , it is desirable to detect andavoid collisions before they occur to prevent premature wear and/ordamage to the robotic arms.

A. System Modelling for Collision Detection and Avoidance

Aspects of this disclosure relate to systems and methods for collisiondetection and avoidance. Specifically, implementations of the roboticsystems described herein can be configured to model the robotic systemfor use in collision detection and avoidance. While certain aspect ofthe modeling of the robotic system relate to the modelling of roboticarms as an example, aspects of this disclosure can also be used to modelother objects of the having measurable dimensions, such as the platformsupporting the patient, the adjustable arm support, the rail, thecolumn, etc.

In certain implementations, the system may form a model of the roboticsystem by breaking down the robotic system into a set of rigid sectionscalled links that are connected by motors, which in kinematics arereferred to as connection joints. At each of these joints, the systemcan include an encoder configured to generate a signal that isindicative of the relationship between two adjacent links. There aremany different types of encoders that can be used, including rotational,linear, magnetic, resistance-based, and/or optical encoders. The systemcan build a model of the robotic system by connecting alternating linksand joints, starting from the fixed base of the robotic system out toeach tool tip location or pose of platform. Thus, the system can build afull model of what the robotic system looks like at any given timeduring a medical procedure using the physical shape/size of each linkand the signals received from each of the encoders.

FIG. 21 illustrates an example view of a model of a robotic system inaccordance with aspects of this disclosure. The model 200 includes aplurality of links that model a platform 205, adjustable arm support(s)210, and a plurality of robotic arms 215. The model 200 may includeadditional links that model other components of a robotic system whichare not illustrated in detail, such as one or more medical instruments,a base, etc. In some implementations, the model 200 is formed based on aseries of rigid transformations (e.g., based on the relative size ofeach link) for each of the links 205-215 and the distance or anglebetween each of the links 205-215 (e.g., the joint angle(s) read fromthe encoders). The illustration of the model 200 in FIG. 21 is ahuman-viewable representation of the model 200 which can be generatedusing, for example, a CAD model drawn for each link with software usedto rotate the links so that the links line up with the correspondingjoint angles. The computer generated image of the model 200 may lookvery much like the actual hardware of the robotic system at a givenpoint in time. In some implementations, the model 200 maintained by therobotic system may not be stored in a human-viewable format.

In some implementations, the system may generate a human-viewable modeland provide the model to be viewed by a clinician (e.g., in the viewerof the clinician console or the clinician assistant console). In otherimplementations, the model is not viewable by a clinician, but can berunning behind the scenes in the system. The clinician may be capable ofpulling up a view of the model when the model is hidden from view.

Using the model of the robotic system, the system may be able to performcertain actions based on the current configuration of the roboticsystem. Advantageously, one action that the system can perform isdetecting when two pieces of hardware are about to collide and preventthe pieces of hardware from colliding. In certain implementations, themodel may also include modeled representations of objects which are nota part of the robotic system (e.g., medical accessories, the patient,etc.) in order to prevent collisions between the robotic arms and themodeled objects.

One aspect of providing for collision detection and avoidance using amodel may involve the system determining how close each link is tocolliding with every other link in the system. There are a number ofdifferent techniques that can be used to determine how close each linkis to each other link. In one implementation, the system can use the CADmodel directly to determine these distances. In another implementation,the system can generate an approximation of the model based on the CADmodel which can be used to speed up computation of the distances betweenlinks. One technique for approximating the CAD model involves generatingan approximation for each link using a geometric form approximation foreach link. In one implementation, the links may be approximated as“capsules.” In other implementations, geometric form(s) used in theapproximation can include using cylinders, rectangles, cuboids, etc. Thesystem can efficiently determine a minimal distance between each capsulein the approximated model using the geometric approximations.

FIG. 22 illustrates a model of a robotic system approximated using ageometric form in accordance with aspects of this disclosure. In themodel 300 of FIG. 22 , each link is approximated using one or morecapsules to simplify the calculation of the distances between the links.For example, two of the links forming a robotic arm 305 can be modelledusing two capsules 310 and 315. The capsules 310 and 315 overlap and canbe moved longitudinally with respect to each other in accordance with achange in the distance between the corresponding links, which ismeasured using an encoder arranged between the links. Similarly, theplatform 320 can be modelled using a plurality of capsules 325, whichcan overlap and may be able to move with respect to each other to modelmovement of the platform 320.

FIG. 23 illustrates an example of an unavoidable collision which can bedetected using a model of a robotic system in accordance with aspects ofthis disclosure. An unavoidable collision generally refers to acollision for which there is no action that the system can take toachieve the commanded movement without a collision occurring. Ingeneral, there may be two points defined that cannot be changed duringactive surgery. The first point is the remote center of motion (RCM)which can be defined when a robotic arm is docked to an access point(e.g., a cannula). The RCM may be the point where the cannula passesthrough the body wall and the system does not normally allow formovement of the RCM since this may cause trauma to the patient (unlessunder explicit user command).

The second point is the medical tool end effector tip location andorientation which can be defined based on commands received from theuser driving the system. With these two points defined the systemcontrols movement of the ADM to in order meet both of these points. Inorder to meet all possible end effector positions, the system can movethe ADM through a hemi-sphere centered upon the port location.Typically, ports are placed such that two or more of these hemi-sphereswill intersect one another, leading to the possibility of unavoidablecollisions for certain commanded end effector poses.

In the example unavoidable collision 400 illustrated in FIG. 23 , afirst set of modeled links 405 form a first robotic arm and a second setof model links 410 for a second robotic arm. A first subset 406 of thefirst links 405 have collided with a second subset 411 of the secondlinks 410 at a number of collision points 415. The collision 400illustrated FIG. 23 is an unavoidable collision since there are no otherposes for the first and second robotic arms which would achieve the sameend effector poses without a collision between some portion of the firstlinks 405 and the second links 410.

FIG. 24 illustrates an example of an avoidable collision which can bedetected using a model of a robotic system in accordance with aspects ofthis disclosure. While there may be only one AMD position that defineseach medical instrument end effector position, there are often manyrobot arm positions for each ADM position. The robot arm(s) can includeat least six joints to achieve any spatial and rotational pose commandedby the user. In certain implementations, the robotic arm(s) each have atleast seven joints, with the additional joints over six being termedredundant joint(s) since the movement provided by the redundant jointscan be accomplished by a combination of motions of the other joints. Theredundant joint(s) can be used with the other joints in combination tocancel out any motion on the redundant joint. For example, the systemcan use both ADM roll and linear bar motion together we can swing theelbow of the robotic arm without the end effector of the medicalinstrument moving. This repositioning of the robotic arm without medicalinstrument end effector motion is called a null space motion. The systemcan control null space motion while also fully controlling the medicalinstrument end effector and thus actively while the user is driving toadvantageously reposition the robotic arm, which can be used to avoidcollisions.

In the avoidable collision 500 of FIG. 24 , a first set of modeled links505 form a first robotic arm and a second set of model links 510 for asecond robotic arm. A first subset 506 of the first links 505 havecollided with a second subset 511 of the second links 510 at a collisionpoint. The collision 500 illustrated FIG. 24 is an avoidable collisionsince the first links 505 and/or the second links 510 can be moved intoa different pose while maintaining the same end effector poses. Thus, incertain implementations, the system can detect that an avoidablecollision, such as the collision 500, is imminent and move one or moreof the first links 505 and the second links 510 to avoid the collision.Examples of systems and methods for avoiding such a collision aredescribed in detail below.

FIG. 25 is a flowchart illustrating an example method operable by arobotic system, or component(s) thereof, for detecting and avoidingcollisions in accordance with aspects of this disclosure. For example,certain steps of method 600 illustrated in FIG. 25 may be performed byprocessor(s) and/or other component(s) of a medical robotic system(e.g., robotically-enabled system 10) or associated system(s). Forconvenience, the method 600 is described as performed by the “system” inconnection with the description of the method 600.

The method 600 begins at block 601. At block 605, the system accesses amodel of a first set of links and a second set of links of a roboticmedical system. For example, the model may be similar to the model 200of FIG. 21 or may be a geometric approximated model such as the model300 of FIG. 22 . In some implementations, the first set of links includea first robotic arm and the second set of links include a second roboticarm. However, in other implementations, the first and/or second set oflinks may include a moveable patient platform, an adjustable armsupport, etc.

At block 610, the system controls movement of the first set of links andthe second set of links based on input received by a console of therobotic medical system. In certain implementations, the console mayinclude a controller such as controller 182 of FIG. 19 . At block 615,the system determines a distance between the first set of links and thesecond set of links based on the model. The determined distance may bethe minimum distance between the first set of links and the second setof links. In some implementations, the system may determine the minimumdistance between each pair of links in the first set of links and thesecond set of links.

At block 620, the system detects and avoids a collision between thefirst set of links and the second set of links based on the determineddistance. For example, the system may avoid the collision by performingan action the prevent the collision, which may include the systemprevent further movement of the first set of links and the second set oflinks. The action can also involve actively avoiding the collision vianull space movement of the first set of links and/or the second set oflinks. The method 600 ends at block 625.

In some circumstances, a robotic system can be configured to move one ormore links of the robotic arm within a “null space” to avoid collisionswith nearby objects (e.g., other robotic arms) while the ADM of therobotic arm and/or the RCM are maintained in their respectiveposes/positions. The null space can be viewed as the space in which arobotic arm can move that does not result in movement of the ADM and/orthe RCM, thereby maintaining the position and/or the orientation of themedical tool. In some implementations, a robotic arm can have multiplepositions and/or configurations available for each pose of the ADM,allowing for null space movement of the robotic arm without affectingend effector pose. For example, when no medical instrument is coupled toan ADM, the robotic arm can maintain the ADS pose/position while movingthe robotic arm in null space. As another example, when a medicalinstrument is coupled to the ADM, the robotic arm can maintain both theADM and RCM while moving the robotic arm in null space.

B. Collision Detection and Avoidance—Cutoff Distance

In certain implementations, the system can prevent the collision of twolinks of the robotic system by comparing the distance between the twolinks to a threshold distance and prevent the two links from movingtowards each other when the distance between the links is less than thethreshold distance. For example, each link in the system can have aminimum distance called the cutoff distance define such that if twolinks move within the cutoff distance, the system will command thehardware associated with the two links (e.g., the motors controllingmovement of the links) to stop motion. An example of the cutoff distance825 is illustrated in FIG. 27 , which is described in detail below.

In some implementations, the system can detect when a commanded movementof either one of the robotic arms would put the robotic arms within thecutoff distance and prevent the commanded movement from occurring. Thesystem can continuously update the model based on the signals receivedfrom the joint encoders, and thus, the system can continuously measurechanges in the distances between the modeled links. Thus, depending onthe implementation, the system can detect changes in the distancesbetween the modeled links without measuring the actual movement (e.g.,changes in velocity) of the links. By detecting a commanded movementthat would have resulted in two links being within the cutoff distance,the system can advantageously prevent the links from touching and placethe system in a faulted state. When an input that includes a commandedmovement to move away from the collision, the system can allow the userto command further movements of the links with normal moving hardware.

After the system has determined that two links are within the cutoffdistance or will be moved within the cutoff distance based on acommanded movement, the system can provide feedback to the user via aclinician console. In some implementations, the feedback can includehaptic feedback which, for example, can be provided via a controllersuch as the controller 182 of FIG. 19 . For example, the system canapply a haptic force to the user's hand via the controller that willdiscourage the user from moving further into the collision. The systemcan also display a warning on a viewer of the clinician console that acollision is imminent or has occurred. By providing feedback via theviewer, the system can advantageously provide an indication of thecollision to the user without the user having to remove his/her headfrom the clinician console viewer. In some implementations, the visualfeedback can also indicate one or more action(s) that the user canimplement to correct or avoid the collision. By providing the hapticand/or visual feedback to the user, the system can provide feedback thatcan advantageously induce the user to instinctively move away from thecollision point and back into areas where the user can freely operatethe robotic arms. By providing haptic feedback via the controller and/orvisual feedback via the viewer, the system can provide information tothe user regarding accidental collisions without the user having todisengage from the console. This can enable the user to continue tocontrol the robotic system without a break in concentration and continuewith any work that is inside of the workspace.

C. Collision Detection and Avoidance—Trigger Distance

In addition to determining whether one or more arms have entered into acutoff distance, the system can also use the modeled robotic system todetermine whether one or more links have entered into a triggerdistance, which is greater than the cutoff distance. In contrast topreventing movement of the robotic arms the arms are within the cutoffdistance, the system can take one or more actions to avoid the collisionin response to the arms being separated by less than the triggerdistance, thereby mitigating the risk of collision. For example, uponentering a trigger distance, one or more arms may use null-space motionwhile maintaining the corresponding medical tool's remote center ofmotion in order to avoid a collision. In other words, upon two roboticarms entering a trigger distance, the system can automaticallyreposition one or more of the arms such that the commanded motion isstill executed and a collision never happens due to the movement in nullspace. The trigger distance may be the minimal distance between twolinks before the system takes avoidance action, such as null spacemovement. An example of the trigger distance 820 is illustrated in FIG.27 , which is described in detail below.

FIGS. 26A and 26B illustrate an example sequence of actions when atrigger distance is reached in accordance with aspects of thisdisclosure. At an initial point in time 700 illustrated in FIG. 26A, thesystem is moving a first robotic arm 705 and the associated firstmedical instrument based on a commanded movement in the direction of thearrow. For example, the user may input a commanded movement for thefirst robotic arm 705 and the first medical instrument with a leftgimbal and input a commanded movement for a second robotic arm 710 andthe associate second medical instrument with a right gimbal.

As shown in FIG. 26A, the system may have received a command to move thefirst robotic arm 705 to perform a particular function, thereby bringingcertain points on the first and second robotic arms 705 and 710 within atrigger distance of each other. Once the first and second robotic arms705 and 710 are within the trigger distance, one or more of the firstand second robotic arms 705 and 710 can use null space movements (e.g.,via its redundant joints) for collision avoidance as shown in the imageof the subsequent point in time 701 in FIG. 26B. As shown in FIG. 26B,the base joint of the second robotic arm 710 is slid along an adjustablearm support 715, thereby providing collision avoidance via null spacemovement (e.g., without moving the end effector of the medicalinstrument associated with the second robotic arm 710). As shown in FIG.26B, that the end effector of the second medical instrument associatedwith the second robotic arm 710 has not moved—only the proximal jointsfor null space motion and collision avoidance have moved.

Accordingly, by detecting that two links have moved within a triggerdistance of each other, the system can avoid certain types of collisionsby taking certain actions (such as null space movement) without needingto inform the user of the potential collision.

The trigger distance can be set to be larger than the cutoff distance toensure that avoidance can be triggered before stopping further movementof the robotic links. The system can use to model to determine not onlywith the minimum distance between two links which may lead to acollision, but also the points at which the two links will collide.Using the distance and the point of collision, the system can determinewhether null space motion will increase the distance between the twolinks at the collision point. If such a null space motion exists, thesystem can execute the null space motion before the two links enter thecutoff distance, avoiding the collision entirely.

FIG. 27 illustrates the cutoff and trigger distances for a modeled linkin accordance with aspects of this disclosure. In particular, FIG. 27illustrates the cross-sections of a first link 805 and a second link 810which are separated by a current (minimum) distance 815. A triggerdistance 820 and a cutoff distance 825 are shown surrounding the firstlink 805. Although not illustrated, the second link 810 may also have atrigger distance and a cutoff distance, which may or may not have thesame values as the trigger distance 820 and the cutoff distance 825associated with the first link 805. As described herein, when anotherlink (such as the second link 810) penetrates the trigger distance 820of the first link 805, the system may take an action to avoid collisionwith the other link. Similarly, when the other link penetrates thecutoff distance 825, the system may take an action to prevent thecollision with the other link, for example, by preventing furthermovement towards the collision. For example, the system can determinethat a commanded input received by the console would result in adecrease in the distance between the links, and prevent further movementin response to the determination. In contrast, when the systemdetermines that the commanded input received by the console would resultin an increase in the distance between the links, the system can controlmovement of the links based on the received input and the determination,thereby allowing the links to move away from the collision.

In some implementations, the cutoff distance (e.g., when the roboticarms will stop) can be, for example, up to 10 mm, up to 15 mm, up to 20mm, or greater. In some embodiments, the trigger distance (e.g., whennull-space motion can occur for collision avoidance) can be, forexample, up to 5 mm, up to 10 mm, up to 15 mm, or greater. In certainimplementations, when the current cutoff distance is 15 mm, the triggerdistance can be 20 mm, such that a 5 mm gap is established between thecutoff distance and the trigger distance. The 5 mm gap can be enoughroom to move the links/robotic arms away from each other faster than atypical command to move the links/arms together. However, if the systemreceives a command to move the robotic arm together faster than nullspace movement can move the robotic arms apart, the robotic arms maybreach the cutoff distance causing the robotic arms to briefly stopfollowing input commands. However, the system will continue collisionavoidance via null space movement even while the robotic arms are withinthe cutoff distance resulting in moving the arms apart. Once the roboticarms have been moved to be separated by more than the cutoff distance,the robotic arms would resume following the user command to movetogether. The user may experience this stop and start of movement as theconsole arms feeling heavy and having slowed motions. If the systemdetects that an arm has two opposing collisions, then the system may notbe able to avoid the collision with null space motion and the systemwill stop motion once the cutoff distance has been hit. When the systemprevents further motion due to a cutoff distance breach, the system canprovide haptic force feedback to the user to inform the user of the needto move one of the tools in the opposite direction to allow the other tomove away from the collision.

In some implementations, the system can be pre-programmed with thecutoff distance and/or trigger distance. In other implementations, auser can manually program a cutoff distance and/or trigger distance.Depending on the implementation, the cutoff distance and/or triggerdistance may be the same for each link, or may be set on a link-by-linkbasis.

FIG. 28 is a flowchart illustrating an example method operable by arobotic system, or component(s) thereof, for detecting and avoidingcollisions using a cutoff distance in accordance with aspects of thisdisclosure. For example, certain steps of method 900 illustrated in FIG.29 may be performed by processor(s) and/or other component(s) of amedical robotic system (e.g., robotically-enabled system 10) orassociated system(s). For convenience, the method 900 is described asperformed by the “system” in connection with the description of themethod 900.

The method 900 begins at block 901. At block 905, the system controlsmovement of the first set of links and the second set of links based onthe input received by a console. The system may include the first set oflinks, the second set of links, and the console, which is configured toreceive input commanding motion of the first set of links and the secondset of links.

At block 910, the system determines a distance between the first set oflinks and the second set of links based on the model. The model may bestored in memory and may model the first set of links and the second setof links.

At block 915, the system determines that the distance between the firstset of links and the second set of links is less than a cutoff distance.At block 920, the system prevents a collision in response to determiningthat the distance between the first set of links and the second set oflinks is less than the cutoff distance. The method 900 ends at block925.

There are a number of advantages that can be achieved according tovarious implementations of this disclosure. For example, by using thecutoff distance and the trigger distance as defined herein, the systemcan control the robotic arms to take no unnecessary motions when outsideof the trigger distance, thereby minimizing the amount of robotic armmotion when collision(s) are not imminent. Inside of the triggerdistance, yet outside the cutoff distance, the system can use null spacemotions to attempt to move the links away from the collision, withoutincreasing the cognitive load of the user. By setting the triggerdistance to be sufficiently small, the robotic arm motions commanded bythe system will be instinctive and staff within the operating room willbe able to visualize the cause of the actions (e.g., the potentialcollision). The user will tend to be unaware that these null spacemotions are happening to avoid a collision. When the cutoff distance isreached the system can stop further motion of the robotic arms towardsthe collision, inform the user informed visually, and provide a hapticeffect to guide the user toward a resolution of the collision withminimal distraction to the user's workflow. For example, the system candetermine that a commanded input received by the console would result ina decrease in the distance between the links, and provide the hapticfeedback in response to the determination.

D. Collision Detection and Avoidance—Global Optimization

In other implementations, the system can detect and avoid collisionswithout the use of a cutoff distance and a trigger distance as describedherein. In particular, the system may implement a global optimizationalgorithm. The global optimization may involve adding all the links andjoints into a single kinematic model and applying a metric to thekinematic model that keeps all links in an optimal configuration. In oneimplementation, the metric can be defined to maintain all of the linksas far away from all collisions as possible. For example, the metric caninclude a configuration in which the first set of links and the secondset of links are at a maximum distance. Depending on the implementation,the optimal configuration algorithm may also take into considerationother optimization goals, such as ensuring that the pose of the roboticarms has sufficient stability. Thus, the global optimization algorithmmay try to find an optimal configuration that optimized a plurality ofdifferent metrics, including maintaining the links as far away from eachother as possible.

In other implementations, the metric can be defined by adding virtualfixtures onto the modeled links that are theoretical points that systemshould work to avoid. In some implementations, the system can also useeither a determined velocity or energy and distance of the links todetermine that two or more links are moving towards a collision andavoid the collision. If the system is unable to use the globaloptimization algorithm to converge on a solution that does avoid allcollisions, the system may stop motion of links of the system, therebypreventing the collision(s).

Implementations which solve such a global optimization algorithm mayinvolve the use of additional computational complexity compared to thecutoff and/or trigger distance-based implementations. The globaloptimization solution may also involve addition null space movementseven when relatively far away from a collision, making it difficult tominimize robotic arm motion when the arms are not near a collision. Itcan be desirable to have substantially stationary robotic arms wherepossible, for example, such that the motion of the robotic arms ispredictable to people in the operating room.

3. Implementing Systems and Terminology

Implementations disclosed herein provide systems, methods and apparatusfor collision detection and avoidance.

It should be noted that the terms “couple,” “coupling,” “coupled” orother variations of the word couple as used herein may indicate eitheran indirect connection or a direct connection. For example, if a firstcomponent is “coupled” to a second component, the first component may beeither indirectly connected to the second component via anothercomponent or directly connected to the second component.

The functions for collision detection and avoidance described herein maybe stored as one or more instructions on a processor-readable orcomputer-readable medium. The term “computer-readable medium” refers toany available medium that can be accessed by a computer or processor. Byway of example, and not limitation, such a medium may comprise randomaccess memory (RAM), read-only memory (ROM), electrically erasableprogrammable read-only memory (EEPROM), flash memory, compact discread-only memory (CD-ROM) or other optical disk storage, magnetic diskstorage or other magnetic storage devices, or any other medium that canbe used to store desired program code in the form of instructions ordata structures and that can be accessed by a computer. It should benoted that a computer-readable medium may be tangible andnon-transitory. As used herein, the term “code” may refer to software,instructions, code or data that is/are executable by a computing deviceor processor.

The methods disclosed herein comprise one or more steps or actions forachieving the described method. The method steps and/or actions may beinterchanged with one another without departing from the scope of theclaims. In other words, unless a specific order of steps or actions isrequired for proper operation of the method that is being described, theorder and/or use of specific steps and/or actions may be modifiedwithout departing from the scope of the claims.

As used herein, the term “plurality” denotes two or more. For example, aplurality of components indicates two or more components. The term“determining” encompasses a wide variety of actions and, therefore,“determining” can include calculating, computing, processing, deriving,investigating, looking up (e.g., looking up in a table, a database oranother data structure), ascertaining and the like. Also, “determining”can include receiving (e.g., receiving information), accessing (e.g.,accessing data in a memory) and the like. Also, “determining” caninclude resolving, selecting, choosing, establishing and the like.

The phrase “based on” does not mean “based only on,” unless expresslyspecified otherwise. In other words, the phrase “based on” describesboth “based only on” and “based at least on.”

The previous description of the disclosed implementations is provided toenable any person skilled in the art to make or use the presentinvention. Various modifications to these implementations will bereadily apparent to those skilled in the art, and the generic principlesdefined herein may be applied to other implementations without departingfrom the scope of the invention. For example, it will be appreciatedthat one of ordinary skill in the art will be able to employ a number ofcorresponding alternative and equivalent structural details, such asequivalent ways of fastening, mounting, coupling, or engaging toolcomponents, equivalent mechanisms for producing particular actuationmotions, and equivalent mechanisms for delivering electrical energy.Thus, the present invention is not intended to be limited to theimplementations shown herein but is to be accorded the widest scopeconsistent with the principles and novel features disclosed herein.

What is claimed is:
 1. A robotic medical system, comprising: a link of arobotic arm; and a processor configured to: control movement of the linkbased on a received input; determine a distance between the link andanother object during the movement; and responsive to the distance beingwithin a threshold, adjust the movement of the link to avoid a collisionbetween the link and the another object.
 2. The robotic medical systemof claim 1, wherein the processor is configured to determine thedistance between the link and the another object using a model of thelink.
 3. The robotic medical system of claim 2, wherein the model is amodel of the robotic arm.
 4. The robotic medical system of claim 1,wherein the threshold is a cutoff distance, and wherein the processor isconfigured to cease the movement of the link to avoid the collisionresponsive to the distance being less than the cutoff distance.
 5. Therobotic medical system of claim 1, wherein the threshold is a triggerdistance, and wherein the processor is configured to adjust the movementof the link to avoid the collision responsive to the distance being lessthan the trigger distance.
 6. The robotic medical system of claim 1,wherein the processor is configured to adjust the movement of the linkby preventing movement of the link.
 7. The robotic medical system ofclaim 1, wherein the another object is another robotic arm or anotherlink.
 8. A robotic medical system, comprising: a link of a robotic arm;and a processor configured to: control movement of the link based on areceived input; determine a distance between the link and another objectduring the movement; and responsive to the distance being within athreshold, move the link in null space to avoid a collision between thelink and the another object.
 9. The robotic medical system of claim 8,wherein the processor is configured to determine the distance betweenthe link and the another object using a model of the robotic arm. 10.The robotic medical system of claim 8, wherein the processor isconfigured to move the link in null space responsive to the distancebeing less than a trigger distance.
 11. The robotic medical system ofclaim 8, wherein the processor is configured to predict whether the linkand the another object will collide if the link is moved according tothe received input, and wherein the processor is configured to adjustmovement of the link responsive to the prediction.
 12. The roboticmedical system of claim 8, wherein the processor is configured to stopmovement of the link responsive to the distance being less than a cutoffdistance.
 13. The robotic medical system of claim 8, wherein the anotherobject is another link.
 14. A robotic medical system, comprising: a linkof a robotic arm; and a processor configured to: receive an inputcommanding motion of the link; predict whether moving the link accordingto the received input commanding motion would place the link within athreshold distance of another object; and control movement of the linkbased on the prediction.
 15. The robotic medical system of claim 14,wherein the processor is configured to control the movement of the linkby moving the link in null space.
 16. The robotic medical system ofclaim 14, wherein the processor is configured to control the movement ofthe link by preventing movement of the link in accordance with the inputcommanding motion.
 17. The robotic medical system of claim 14, whereinthe processor is configured to use a model of the link to perform theprediction.
 18. The robotic medical system of claim 14, wherein theprocessor is configured to predict whether the link will collide withthe another object if the processor moves the link based on the inputcommanding motion.
 19. The robotic medical system of claim 18, whereinthe processor is configured to determine whether a specific movement ofthe link would increase a distance between the link and the anotherobject at a point where the link is predicted to collide with theanother object.
 20. The robotic medical system of claim 19, wherein theprocessor is configured to move the link according to the specificmovement based on a determination that the specific movement of the linkwould increase the distance between the link and the another object.